Broken video player

[fr0zert]

Recently found that on one site are broken player, no buttons and no video window.
I think the problem is that custom css parameters have the same names as elements on the site, or something like that, but this is just my guess.
Site: rezka.ag (they have many different domains hdrezka and etc.)

broken:

normal(without css):

[Bali10050]

userContent.css can have an effect on websites, but I put everything in media-tags limited to some urls, so it shouldn't do anything outside of about: and chrome: unless there's a typo somewhere. Try checking it in a new profile, until I get home to fix it.